ICMR experts have advised against 'revenge travel' and warned that a rise in social gatherings by tourists or mass congregations due to social, religious or political events may set off the third COVID-19 wave in India.
Researchers said that data from Himachal Pradesh suggests that in a typical holiday season, tourism can increase the population by 40 percent.
"Taking this into consideration, the third-wave peak can increase by up to 47 percent during the holiday season and can occur two weeks earlier compared to a scenario of easing restrictions in the absence of holiday travel," researchers said.
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The opinion piece titled 'Responsible travel to and within India during the COVID-19 pandemic' was authored by Balram Bhargava, Samiran Panda and Sandip Mandal from ICMR and Nimalan Arinaminpathy from Imperial College London.
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"A sudden increase in population density due to incoming tourists or mass congregations due to social, political or religious reasons can worsen the third wave scenario," the researchers said in the opinion piece.
India's second wave of COVID-19 was severe but showed varying impacts in different states. Smaller states with rarefied populations witnessed not only less intense spread than was apparent at the national level but also delayed attainment of the second peak, they observed.
Giving examples of popular tourist destinations such as Manali and Darjeeling, the researchers said that observations indicate increasing opportunities for transmission in areas where population-level immunity has not yet accumulated to the same levels as elsewhere in the country.
Proposing 'responsible travel', researchers said mask use and observing social distancing norms by tourists can have important effects in mitigating the risk of disease transmission.
Vaccine status can also play an important role in eligibility to travel, with some caveats, researchers said.
"Vaccine passports have limitations, arising from uncertainties about how the nature and strength of vaccine-induced immunity would change over time. Also, despite being the world's largest producer of COVID-19 vaccines, India faces the challenge of having the world's second-largest population to vaccinate. Nonetheless, as vaccination coverage scales, vaccine status can play an increasingly important role in eligibility to travel," they said.
Immunization planning may also benefit from prioritizing the local population in holiday destinations. Maintaining surveillance in at-risk settings, ensuring that virological testing is maintained even during apparent low infection activity will be important, the opinion piece stated.
Observing that no national guideline exists on restrictions about domestic travel, the researchers said it may be helpful for holiday-destination states to get guidance on how they can best mitigate travel-related risks.
"With the possibility of a severe third wave in India still looming, it remains critical to recognize and mitigate the risks involved. A shared sense of responsibility, amongst visitors, residents and local authorities, will go a long way towards protecting the welfare of the country as a whole," the researchers added.
(With PTI inputs)